3-D Interfacial Stress Decoupling Method Based on Graphene Foam

Abstract

Measuring the interfacial stress between robots and objects is a prerequisite for robots to finish complicated works. In general, the interfacial stress is the 3-D interfacial stress which not only couple with the vertical normal interfacial stress but also the parallel shear interfacial stress. It is very important to develop a method to decouple the 3-D interfacial stress. This paper presents a measurement method that was able to decouple the measurement of the 3-D interfacial stress components. To implement the method, a 3-D interfacial stress sensor was fabricated based on graphene foams and superelastic materials. A high-resolution multichannel resistance measurement circuit was developed, and experiments were carried out with 3-D stress simulation equipment. The results showed that the sensor was capable of measuring z-direction normal stress at a range of 0-21 kPa with a sensitivity of 0.029 kPa <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> and x- and y-direction shear stresses at a range of 0-12.5 kPa with sensitivities of 0.020, 0.019, 0.018, and 0.019 kPa <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> , and the measurement circuit was capable of measuring a range of 100 Ω - 100 MQ with a resolution of 1%. This method can be utilized in robots to decouple the measurement of the 3-D interfacial stress components.